Patent GB-585802-A (GB)
Title: Manufacture of new mono-azo-dyestuffs
IPC: C09B62/66
Filed: 1943-09-22
Abstract: Monoazo dyestuffs are manufactured by coupling a tertiary aromatic amine of the general formula <FORM:0585802/IV/1> wherein the alkylene radicals may be the same (preferably) or different and wherein R represents an aromatic nucleus of the benzene series capable of coupling in p-position to the substituted amino group, with an unsulphonated p-nitrodiazo-compound of the benzene series, and, before or after coupling, converting the tertiary amine or the dyestuff into a mixture of the acid sulphuric mono- and di-esters thereof by treating one molecular proportion thereof with more than one but not more than substantially 1.5 molecular proportions of a sulphonating agent, e.g. sulphuric or chloro-sulphonic acid, preferably in the presence of an organic solvent indifferent to chlorosulphonic acid or sulphur trioxide, e.g. carbon tetrachloride, tetrachloroethane or trichloroethane.  Suitable tertiary amines are the N-di-b -hydroxyethyl-,g  - hydroxy - n - propyl- and - d  - hydroxy-n-butyl derivatives of aniline and its 3-methyl-, 3-chloro-, 2- and 3-methoxy-, 2-methoxy-5-methyl-, 2 : 5-dimethoxy- and 2 : 5-diethoxy-derivatives.  The products, especially in the form of their salts, e.g. with alkali metals or ammonium, dye cellulose esters and ethers, chiefly in red to brown, violet and blue shades, and are also suitable for dyeing synthetic fibres having the character of animal fibres, e.g. superpolyamide or super-polyurethane fibres.  In examples: (1) 3-methyl - N - di - b  - hydroxyethylaniline is warned with about I-3 molecular proportions of chlorosulphonic acid in carbon tetrachloride and the product is coupled with diazotized 2-cyano or 2 : 6-dichloro-4-nitraniline; (2) the diazo components in (1) are replaced by 2-cyano-4 : 6-dinitraniline; (3) the dyestuff p-nitraniline -->N-di-b -hydroxyethylaniline is warmed with about 1.1 molecular proportions of chloro-sulphonic acid in tetrachlorethane; a table shows the shades obtained on cellulose acetate artificial silk with the sodium salts of the esters obtained by the action of 1.2 molecular proportions of sulphonating agent on the dyestuffs 2 - methoxy - 4 - nitraniline-->N - di - b  -hydroxyethylaniline, 2-cyano-4 : 6-dinitraniline--> 2 - methoxy - 5 - acetylamino - N - di - g  - hydroxy-n-propylaniline, and 2-chloro-4-nitraniline -->N - di - (g  - hydroxy - a  - methyl - n - propyl) aniline or N-b -hydroxyethyl-N-(g -hydroxy-a  - methyl - n - propyl) - aniline, and of 1.3 molecular proportions of sulphonating agent on the dyestuff 2-cyano-6-chloro-4-nitraniline -->3 - methyl - N - di - b  - hydroxyethylaniline, and the ammonium salt of the ester obtained by the action of 1.25 molecular proportions of sulphonating agent on the dyestuff 2-cyano-4 : 6-dinitraniline-->3-methyl-N-di-b -hydroxyethylaniline; (4) cellulose acetate artificial silk is dyed violet with the first dyestuff of (1) from a neutral bath containing sodium sulphate; (5) superpolyamide yarn made from nylon is dyed blue with the product of (2) from a similar bath.  Additional diazo components specified are 2 : 4-dinitraniline, 2-methyl-4-nitraniline, 6-chloro-2 : 4-dinitraniline and 2-methylsulphone-4-nitraniline and -4 : 6-dinitraniline.  N-Di-g -hydroxy-n-propyl- and -d -hydroxy-n-butyl-anilines are obtainable by condensing one molecular proportion of the appropriate primary amine, e.g. aniline or 2-methoxy-5-acetyl-amionaniline, with two of 3-chloropropanol-1 or 4-chlorobutanol-1, e.g. in the presence of calcium carbonate. N-Di-(g -hydroxy-a -methyl-n-propyl)-aniline is obtainable by condensing aniline with two molecular proportions of 3-chlorobutanol-1 in the presence of calcium carbonate.  N-b -Hydroxyethyl-N-(g -hydroxy-a -methyl-n-propyl)-aniline is obtainable by condensing aniline with one molecular proportion each of ethylene chlorhydrine and 3-chlorobutanol-1 in the presence of calcium carbonate.  Specifications 181,750, 237,739, [both in Class 2 (iii)], and 546,665 are referred to.  The Specification as open to inspection under Sect. 91 comprises also the manufacture of the pure acid sulphuric monoesters, and describes the potassium salt of the ester obtained by the action of one molecular proportion of sulphonating agent on the dyestuff 2-chloro-4-nitraniline-->N-di-b -hydroxyethylaniline, and the ammonium salts of the esters obtained by the action of one molecular proportion of sulphonating agent on the dyestuffs 2 : 6 : dichloro-4-nitraniline or 2-cyano-4-nitraniline--> 3-methyl-N-di-b -hydroxyethylaniline. Refer-ence is also made to the use, as diazo components, of 4-chloro- and 2 : 5-dichloro-aniline, and, as coupling components, of N-di-(hydroxy-n-amyl)-anilines and compounds in which the hydroxyalkyl groups carry further substituents.  This subject-matter does not appear in the Specification as accepted.